Finding a good mechanic or shop that you can trust is very difficult, so when you find one, it pays to stick with them. It’s why I always take my car to the same place every time I have an issue. There have been a couple times when I, or my lovely wife, have brought it in for a minor issue and they sent us on our way without a bill. One time one of us rolled over some tar that stuck to the tire, leading to a bit of a shake and some thumping. We brought it in, they scraped it off, and sent us along free of charge (they didn’t even charge for labor). That’s good service and, when you think about it, it’s how business should be done.

So that’s what makes some of these car maintenance scams so egregious. It’s businesses thinking of the short term, rather than the long term, and wanting to make a quick buck off a sucker. Many of these are scams because they don’t outright rip you off, they just overcharge you for a service you don’t need.

Shampooing Your Engine

I remember when my friend brought his car into the shop for some routine maintenance and the salesperson sold him a service where they’d shampoo his engine. They cleaned the exterior of his engine of the oil, dirt, grease, and grime that every engine in the world has on it (it’s making hundreds of little explosions, of course it’ll get dirty!) for a hundred bucks or two. The service is completely unnecessary, the engine doesn’t need to be shampoo’d and if you really want to clean it, you can buy your own shampoo for less than a hundred bucks or two!

Engine Flush

Whereas shampoo is for the outside, an engine flush is for the guts of the engine. In some cases, an engine flush is necessary if your engine has a buildup of sludge or other gunk. Many places will recommend a flush even when it’s unnecessary because they know most people will just agree to it. The only time you will need an engine flush is if you’ve been driving the car for years and notice a buildup of material under the oil cap. If there is sludge, it’ll get cycled into the motor oil and some of it will collect on the oil cap. If the shop says you need it because your oil is dirty (it gets dirty and loses that nice brown color the moment it cycles through the engine), run.

Clean Your Fuel Injectors

It seems that all the scams are focused on the engine, huh? Well, this one is another classic that preys on the ignorance of drivers. Fuel injectors do need to be cleaned but usually not until they’ve put on a lot of miles (think 100k+), so if you’re looking at a 20,000 mile car and the mechanic says you need them cleaned, they’re full of it. If you are really concerned, you could add fuel injector cleaner to your gas tank on your next fill up (it’s recommended you use it every other oil change, that’s how infrequently) to help assuage your fears.

Gas Saving Devices

They do not work.Consumer Reports[3] has studied this extensively and they have yet to find something that actually improves fuel economy. Don’t accelerate too quickly, don’t slam on the brake, empty your trunk of junk, learn to coast effectively, pick up some tips of hypermilers[4], and don’t buy “gas saving devices.”

Auto Transmission Flush

If you have an automatic transmission vehicle, the mechanic might recommend that you flush and replace it. I’ve known, from when my dad flushed and replaced the transmission fluid in his car, that this is not something you want to do yourself as it can take a lot of time and can get a little messy. But, it’s also something you won’t need until at least 60,000 miles and not even then, if you have a filter (which many cars do). Check with your owner’s manual for how often this should be done.

Those are five of the worst car maintenance scams out there but they are certainly not the only ones. Whenever a mechanic recommends you do something, take it with a grain of salt unless you have the level of trust I have with my mechanic. Even then, double check their recommendations against your manual, online resources, and any car experts you know before you shell out a few hundred bucks for a procedure.

What’s the worst thing a car mechanic tried to pull on you recently? An engine shampoo? Replacing your air filters? Washing your undercarriage?